Conventionally, a technology has been known that determines a likelihood of a collision with an obstacle ahead of a vehicle when the vehicle speed of the vehicle is lower than a predetermined vehicle speed, and depending on the determination, inhibits execution of drive support such as issuing an alarm, and braking automatically (for example, Japanese Laid-open Patent Publication No. H6-1221).
This technology makes it possible to suppress a situation where the drive support is frequently executed in a circumstance where the vehicle travels at a comparatively low vehicle speed due to, for example, traffic congestion, and to suppress a sense of discomfort or the like felt by the driver of the vehicle that could be caused by frequent execution of the drive support.
Incidentally, for example, if the vehicle stops or travels at a comparatively low vehicle speed, and a following vehicle collides with the vehicle from behind, there is a likelihood that the vehicle is pushed out by the following vehicle, and suddenly approaches an obstacle positioned ahead. In such a case, it is desirable to have the drive support executed to avoid a collision with the obstacle ahead of the vehicle.
However, if one adopts a configuration in which the drive support is inhibited if the vehicle speed of the vehicle is lower than a predetermined vehicle speed as done by the technology described in Japanese Laid-open Patent Publication No. H6-1221, the drive support may not be executed at an appropriate timing in the above case. Namely, if the vehicle speed of the vehicle is lower than the predetermined vehicle speed when the vehicle is struck from behind, the drive support is not executed until the vehicle speed of the vehicle becomes greater than or equal to the predetermined vehicle speed after the collision from behind. Therefore, there is a likelihood that the drive support is not executed, or executed but the start timing of the drive support is late.
In view of the above problem, it is an object of at least one embodiment to provide a collision avoidance apparatus that executes drive support to avoid a collision with an obstacle ahead of a vehicle, while avoiding frequently executing the drive support in a circumstance where the vehicle travels at a comparatively low vehicle speed, yet is capable of executing the drive support at an appropriate timing if the vehicle is pushed forward to be accelerated, due to a collision in which a following vehicle strikes the vehicle from behind.